If Steam breaks completely and only shows a black screen:
Steam only displays a black screen in place of WebView elements such as the store & library panels. The issue is caused by an update to freetype2, so the easiest way to solve the problem is to opt into the Steam beta client
Downgrading the freetype2 to version 2.10.4 would be a bad idea with something as important as freetype2 as other packages may break.